Hello champ, G is not rewarding you, there is a difference in what you bid and what you pay as you always pay the lowest possible price per say.

For example you could bid $20 and if everything else stayed the same you would still only pay the current .45

Your bid is at max cpc you wish to pay, so lets say in the event somebody bid a Little higher than the .45 your next bid would raise to cover that up to .60 at which point it will start to slide in the display rankings.

To answer your question, no do not lower your bid unless you want to re adjust your max cpc